Removal of Arsenic in Drinking Water by Iron

Arsenic, a common toxic element is mainly transported in the environment by water. Arsenic in drinking water is of major concern to many of the water util-ities in the world. Numerous studies have examined the removal of arsenic from drinking water through treatment processes such as coagulation-precipi-tation, reverse osmosis and ion exchange. The focus of research has now shift-ed to solve the problems using suitable adsorbents to achieve low level As in drinking water for communities with high raw water arsenic concentration. The determination of arsenic species is also essential for a better understanding and prediction of the toxic and carcinogenic nature of the species present in natural water systems. It is generally known that As(III) is more toxic than As(V) and inorganic arsenicals are more toxic than organic derivatives. The objective of this study was to study the arsenic adsorption behaviour on iron oxide-coated sand (IOCS) and ferrihydrite (FH). Batch studies were conducted using these adsorbents with natural water containing 325 µg/L arsenic, and the removal of approximately 90 % was obtained. The adsorption capacity of the IOCS and F